Braking device for thread for an automatic loom



1962 H. MERK] 3,

BRAKING DEVICE FOR THREAD FOR AN AUTOMATIC LOOM Filed April 12, 1960 4 Sheets-Sheet 1 Dec. 11, 1962 H. MERKI 3,

BRAKING DEVICE FOR THREAD FOR AN AUTOMATIC LOOM Filed April 12, 1960 4 Sheets-Sheet 2 H. MERKl Dec. 11, 1962 BRAKING DEVICE FOR THREAD FOR AN AUTOMATIC LOOM Filed April 12, 1960 4 Sheets-Sheet 3 H. MERKI Dec. 11, 1962 BRAKING DEVICE FOR THREAD FOR AN AUTOMATIC LOOM 4 Sheets-Sheet 4 Filed April 12, 1960 INVENTOR. HERMANN MERKI A TORNEY.

United States Patent Ofifice 3,067,778 Patented Dec. 11, 1962 3,067,778 BRAKING DEVICE FOR THREAD FOR AN AUTOMATIC LOOM Hermann Merki, Ruti, Switzerland, assignor to Ruti Machinery Works Ltd., formerly Caspar Honegger, Ruti, Switzerland Filed Apr. 12, 1960, Ser. No. 21,640

Claims priority, application Switzerland Sept. 11, 1959 7 Claims. (Cl. 139-257) This invention relates to a method and a device for drawing off and holding the outer thread end of a weftbobbin to be put into the shuttle of an automatic loom.

A device of the type has been proposed, incorporating means for mechanically drawing off the end winding from the bobbin core, and pneumatic means for sucking up the thread end. In that respect reference is made, for instance, to the US. Patents Nos. 2,845,957 and 2,872,948.

In these arrangements, in the case of fine yarns and especially silk and synthetic fibers, the thread is again drawn out of the suction device.

Now the present invention relates to a braking device adapted to prevent withdrawal of the thread end from the suction device. As soon as the end winding is drawn off by the thread draw-off device and the thread end is in the suction device, the thread will be'braked immediately ahead of the aperture of the suction pipe.

Accordingly the method provides that the thread end portion, after being drawn off and held, will be braked until the first weft of the bobbin has been picked, while the braking will be stopped incident to beating up the first weft.

The device for carrying out the method principally consists of a stationary member having attached thereto a first and stationary part of a brake, While the second and movable part of the brake includes a member which is controlled in dependence on the movement of a thread draw-off device and the slay of the loom.

Other features of the invention will appear from the following description and claims, taken in conjunction with the accompanying drawing, wherein there are shown purely by way of example two forms of embodiment of the thread-braking device according to the invention.

FIG. 1 shows a side view of the braking device with brake opened;

FIG. 2 is the braking device according to FIG. 1, with brake closed;

FIG. 3 is a top view of the braking device;

FIGS. 4 and 5 show another form of the braking device with brake opened and closed respectively;

FIG. 6 shows a top view of the device according to FIGS. 4 and 5; and

FIG. 7 is a perspective view showing the braking device of the invention associated with a conventional automatic loom.

Referring to the embodiment illustrated in FIGS. 1, 2 and 3, numeral 1 designates a shaft which already exists on the loom for actuating the diagrammatically indicated thread draw-off device 4 and cutter 29', while another shaft 2 is arranged on a stationary carrier 2a which could be connected to the thread draw-off device. The latter is associated with a suction device diagrammatically shown by the pipe 4a. A possible construction of the thread draw-ofi device is shown in FIG. 6 of the US. Patent No. 2,845,957 for example and need not be described in detail here.

As seen in FIG. 7, the slay 11 of a loom is approximately at its anterior dead center position and the weaving shuttle 21 is at the side of the automatic bobbin change. The filling bobbin 22 present in the weaving shuttle 21' has only a small amount of yarn 22a, so that va change of bobbins is about to take place. The bobbin guide of conventional construction and not shown in FIG. 1, extends through a lateral opening of the shuttle 21, and sweeps over the filling bobbin 22' in order to determine the necessity for a bobbin change so as to initiate the change process. The spare bobbins 23' and 24' are in a feed channel 25' in which, under the effect of gravity, they slide down. The lowest bobbin 23 which, (1111'? ing the bobbin change, is to be shot into the shuttle 21' with the help of the hammer 26', the almost empty bobbin 22 being ejected, is secured against premature dropping by conventional means 26a. The shuttle 21 is driven by a picker 27'. In FIG. 1 the period immediately before the shotting in of the bobbin 22' into the shuttle 21' is shown. The conventional cutter 29', which is shiftable by means of a slide 30 on two stationary guide rails 3132 against the shuttle, is in a forward position and open for the cutting of the thread. The filling thread 33 last shot into the weave, indicated by a dash-dot line, runs through the opened cutter 29. The shifting of the cutter 29 indicated, is brought about by a lever 34 which is secured to shaft 1, and by a guide rod 36 which, by means of hinges, is connected with the lever 34' and the slide 30 of the cutter. A pressure spring 37 surrounding the guide rod 36 makes it possible to somewhat shove back the slide with the cutter 29' from the shuttle, without shifting the lever 34'. The slide 30 is provided with an adjustable stop 38 which can strike against the slay 11 and which is so adjusted that contact of the cutter 29 against the wall of the shuttle 21' is prevented. For the closing of the cutter 29' the latter is provided with a roller 40 which cooperates with a stop 41 which is connected with the hammer 26 and in the downward motion of the hammer presses against the roller 40, whereby the cutter portions are closed. The tip bunch 3' of the bobbin 23 ready for shooting into the shuttle 21 is seized in conventional manner by a draw-off device 4. The draw-oh? device 4 is arranged at the end of a tube-shaped holder 47 which is bent twice at right angles so that it has two parts 47a and 4711 running somewhat horizontally and at right angles to one another, as well as a part passing downward. The part 470 of the holder 47, with the aid of bearing parts, is fixed rotatively in the loom frame (not shown).

The casing of the thread draw-off device 4 has mounted thereon a leaf spring 5 representing the one fixed part of the thread brake. The other and movable part of the brake includes a one-armed lever 6 which is rockably mounted on the shaft 2. The shaft 2 and the lever 6 have a torsion spring 6a interposed therebetween, which tends to urge the lever 6 clockwise towards the braking leaf spring 5. Said lever 6 has at its tail end a notch 61: for the roller 7a or contact member of a lever 7 which is pivoted at 2b to the carrier 2a. The extremity of lever 7 remote from the roller 7a coacts with a pawl 10 pivoted at 20 to the carrier 2a and has to this effect a recess 7b which is engageable by a nose 10a of the pawl 10. The axle 20 carries a coil spring 2d which tends to push the pawl 10 towards the lever 7. The pawl 10' is further in operative relationship with a cam finger 11a of the slay 11. The lever 7 is engaged by one end of a spring 8 whose other end is attached to one extremity of a leaf spring 9 mounted on shaft 1.

The action of the braking device is as follows:

The braking device is operated from the shaft 1 and the slay. In the open position of the brake 5, 6 shown in FIG. 1, the cam finger 11a has, upon throw of the reed, reached the position shown, then pushed-down the pawl 10 and released the lever 7 which has moved into the position shown (FIG. 1) in the direction of the arrow B under the influence of spring 8. Thereby the lever 6 has been raised by roller 7a and notch 612 into the open position shown, to thus release the brake 5, 6. Further, the

3 thread draw-off device 4 has drawn the end winding from the bobbin tip 3 (FIG. 3). The leaf spring 9 on shaft 1 takes up the position shown in FIG. 1.

When the bobbin scanner (not shown), ascertains that a change in bobbins is imminent, the change process is initiated in conventional manner. It is to be noted that the bobbin change always takes place at the next shooting of theshuttle 21' into the automatic end position according to FIG. 7. The draw-01f device 4, by means of the holder 47, is moved against the readied bobbin 23' and shifted in axial direction over its end. The tip bunch 3' is stripped off from the bobbin 23' in conventional manner and drawn into the pipe 47a by means of suction. To support the eflect of the suction, the thread leading from the bobbin 23' to the draw-off device 4 must now be clamped between the flat spring 5 and the lever 6. This takes place as follows:

Assoon as the slay is in the foremost position, the bobbin change takes place in conventional manner. The filling thread 22a of the bobbin 22' to be ejected is cut oif by the cutter 29'. For the activation of the cutter 29' the lever 34 is swung in counterclockwise direction, the flat spring 9 being swung in the same direction and, by means of the spring 8, rotates the lever 7 so far about the shaft 2b that the roller 7a engages in the notch 6b of the lever 6. Thereby, under the effect of the torsion spring 6a, the lever 6 can press against the fiat spring 5 and clamp the filling thread.

The thread must now be clamped until the first filling thread has been shot in. As the cutter 29 is in its foremost position only a very short time, the clamping action of the lever 6 must be maintained during the first shooting of the filling by means of the pawl This pawl 10 engages with its nose 10a in the recess 7b of the lever 7 and thus prevents the neutralization of the braking effect of the lever 6 upon the return of the cutter. However, as long as the slay 11 is in the foremost position, the finger 11a prevents the pawl 10* from engaging with its nose 16a with the recess 7b of the lever 7. Therefore, the lever 7 can be withdrawn by the flat spring 9 only after the finger 11a has released the pawl 10. This is brought about as follows:

When the thread draw-off device 4 starts to operate, upon rocking of the shaft 1, the leaf spring 9 comes into the position 9a as in FIG. 2. The tension spring 8 now acts as a compression spring, and the lever 7 is swung into the position shown in FIG. 2, in which it engages with roller 7:: in the notch 6b of lever 6, so that the spring 6a causes the lever 6 to swing downwards, thus pressing the thread end portion A against the leaf spring 5 to brake the thread.

The leaf spring 9 has the following duty:

After drawing off the end winding by the thread drawoff device 4, and when the cutter 29 is shifted, the spring 9 is bent through the amount a; at the same time the cam finger 11a holds the pawl 10 in its lowered position. Simultaneously the cam finger 11a and leaf spring 9 will move in the direction of the arrows D and C respectively. However, when the cutter returns, the lever 7 will only be permitted to move, when the leaf spring 9 has become relaxed by the distance a; but meanwhile the pawl 10 has already come into the position shown by the solid lines and thus prevents movement of the lever 7, so that the thread A remains braked until the beating up of the first thread. This retardation is suflicient for the slay 11 to release the pawl 10. The fiat spring 9 can now be swung back completely without neutralizing the braking effect of the lever 6. After the first filling has been shot and the slay has again reached its foremost position, the thread brake is released by the finger 11a.

-In the embodiment according to FIGS. 4, 5 and 6, the carrier 22a corresponds to the carrier 2a in FIGS. 1-3, the shaft 22 to the shaft 2, and the shaft 21 to the shaft 1, operating the outer cutter. The shaft 22 is journalled in a support 22b firmly connected to the standard 22a. Nu-

meral 23 designates the bobbin tip from which the end winding is drawn Off, Where upon the thread end is in the thread draw-off device 24 and suction device 24a.

The thread draw-off device 24 has the braking leaf spring 25 attached thereto. The movable counterpart is the lever 26 rockable on shaft 22 through a torsion spring 26a. The support 22b has attached to it a linkage 35 with two horizontal arms each of which has a recess 35a, 35b corresponding vertically, within which a pawl 27 with a notch 27a is movable up and down. The upper arm of the linkage 35 is engaged by a spring 30 whose other end is attached to the lower extremity of pawl 27. Below, said pawl 27 has a control face 27b adapted to cooperate with a cam finger 33a of the slay 33. Mounted in the pawl 27 is a pin 31, on which rests the lever 26 in the open position of the braking device, shown in FIG. 4.

Another arm 35c of the linkage 35 has pivoted thereto, at 23a, a lever 28 which cooperates on the one hand with the pawl 27, and on the other hand with a lever 29 connected to the shaft 21, through the lever-roller 29a.

The action is as follows:

In the open position of the braking device, shown in FIG. 4, the lever 26 is raised by the pin 31, the pawl 27 being drawn both upwards and towards the edge 35d of the recess 35b in the lower arm of the linkage. The lever 29 with its roller 2911 has fallen into the corresponding notch in lever 28.

When the thread draw-off device 24 starts to work, the lever takes up the position shown in FIG. 5, the roller 29a raising the lever 28 on the respective side and pressing the same down on the other side. Thereby the pawl 27 with pin 31 is moved down, so that the lever 26 becomes free and will be swung downwards so as to press the thread end portion A against the leaf spring 25-, thus braking the thread. Incidentally the spring 30 causes the pawl 27 with the notch 27a to engage the nose 35d of the linkage 35 and can only be released at the next throw of the reed by the cam finger 33a which then occupies the dottedline position in FIG. 5.

After the end winding has been drawn off the bobbin tip 23, the lever 29 and cam finger 33a are in the position shown in FIG. 4 and will simultaneously move in the direction of the arrows C and D respectively. Until the roller 29a has passed along the path a, the lever 28 cannot move. In that time, the cam finger 33a has moved so far in the direction of the arrow D, that the spring 30 has caused the pawl 27 to engage the nose 35d. The thread end portion A remains braked between the leaf spring 25 and the lever 26 as pressed down by the spring 26a.

The disclosed braking device is of such design that the thread end certainly cannot be withdrawn from the suction device, and that the thread when tightly pulled does not rupture, but will be partially withdrawn from the brake; this is necessary, inasmuch as for the first pick some thread is always needed from the end winding thread portion. Also the thread in the braking device can participate in the movement of the slay.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim 1s:

1. A braking device adapted to be associated with the automatic bobbin-changing mechanism of an automatic loom for the braking of the drawn olf thread end from a fresh bobbin to be shot into the weaving shuttle, said loom having a frame, a slay, and a pneumatic draw-oft mechanism, said braking device comprising a pair of coopcrating members adapted to clamp the thread therebetween, one of said members being a flat spring secured to the inlet end of said draw-off mechanism and the second of said members being a lever pivotally supported in relation to the loom frame and movable into and out of engagement with said flat spring.

2. A braking device as defined in claim 1, further comprising a pivoted lever acting upon said second member to control its movement into and out of engagement with said fiat spring, said lever being acted upon by a first spring normally holding said second member out of engagement with the first-named member, said first spring being connected to a second flat spring adapted to be connected to a shaft of the loom [for relating the movement of said second member to the movements of the other parts of the loom.

3. A braking device as defined in claim 2, further comprising a pivoted pawl and a finger adapted to be con nected to the slay of the loom for movement into and out of engagement with said pawl, said pawl having a surface positioned for engagement with said lever for selectively holding said lever in the position corresponding to the lowered position of said second member.

4. A braking device as defined in claim 2, wherein said second fiat spring is deflectible by a predetermined amount to apply pressure to said first spring.

5. A braking device as defined in claim 2, wherein said second member is pivoted upon a shaft and has a recess adapted to receive one end of said pivoted lever and an associated cam surface for engagement of said one end of said pivoted lever to move said second member out of 6 engagement with said flat spring upon release of the brake.

6. A braking device as defined in claim 1, further comprising a pawl carrying a contact member engageable with said second member, said pawl being longitudinally displaceable for controlling the movements of said second member into and out of engagement with said flat spring, and a control lever for moving said pawl, said control lever being pivoted by a second member adapted to be mounted upon a shaft of the loom for coordinated movement with other parts of the loom.

7. A braking device as defined in claim 6, further comprising a member for engagement with said pawl for holding said pawl in lowered position and a finger carried by the slay of the loom for engaging said pawl to release said pawl for upward movement, spring means being provided for normally urging said pawl upwardly.

References Cited in the file of this patent UNITED STATES PATENTS 2,566,880 Fiset et al. Sept. 4, 1951 2,608,217 Kronoff Aug. 26, 1952 2,892,470 Corneliusson et a1. June 30, 1959 

